<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script>
    console.log(Math.PI)
    console.log(Math.abs(-1))
    console.log(Math.random())
    console.log(Math.round(123.72))

    /*
        向下取整 最大值是10 最小值是0 Math.random的结果可能为 0.012345...
    */
    console.log(Math.floor(Math.random() * 11))
</script>
</body>
</html>